The industrial Internet of Things and the System-of-Systems engineering paradigm draw increased attention to some of the central challenges of model-based systems engineering when applied for complex industrial scenarios. The paper describes a general position on how the problems of correctness, completeness, and consistency are central to modern model-based solutions in the industry, illustrated by an actual model migration scenario arising in the context of Eclipse Arrowhead which is a industrial System-of-Systems platform. We describe the general challenges and the particular engineering context, offering a detailed description of how they can be tackled with the Cameo systems engineering domain, the Eclipse Modeling Framework, and tool-independent integration solutions such as the IncQuery Suite.

Abstract Designing and reasoning about complex systems such as wireless sensor networks is hard due to highly dynamic environments: sensors are heterogeneous, battery-powered, and mobile. While formal modelling can provide rigorous mechanisms for design/reasoning, they are often viewed as difficult to use. Graph rewrite-based modelling techniques increase usability by providing an intuitive, flexible, and diagrammatic form of modelling in which graph-like structures express relationships between entities while rewriting mechanisms allow model evolution. Two major graph-based formalisms are Graph Transformation Systems (GTS) and Bigraphical Reactive Systems (BRS). While both use similar underlying structures, how they are employed in modelling is quite different. To gain a deeper understanding of GTS and BRS, and to guide future modelling, theory, and tool development, in this experience report we compare the practical modelling abilities and style of GTS and BRS when applied to topology control in WSNs. To show the value of the models, we describe how analysis may be performed in both formalisms. A comparison of the approaches shows that although the two formalisms are different, from both a theoretical and practical modelling standpoint, they are each successful in modelling topology control in WSNs. We found that GTS, while featuring a small set of entities and transformation rules, relied on entity attributes, rule application based on attribute/variable side-conditions, and imperative control flow units. BRS on the other hand, required a larger number of entities in order to both encode attributes directly in the model (via nesting) and provide tagging functionality that, when coupled with rule priorities, implements control flow. There remains promising research mapping techniques between the formalisms to further enable flexible and expressive modelling.

The fourth industrial revolution (Industry 4.0) elevates the complexity and autonomy of industrial systems and engineering environments to levels not seen before. The novel challenges involve not only the software running on the partaking autonomous devices, but also architectural considerations and the technological infrastructure around the entire engineering process. In this paper, complementing the trends in industrial systems design, we propose an approach to toolchain modeling, i.e. an integrated specification for the interoperability of tools along with the holistic architectural framework, designed in the context of the Arrowhead Framework. In particular, we propose an intuitive, yet founded definition for toolchains and their mappings to a versatile engineering process model. Those definitions then serve as a basis for proposing our comprehensive toolchain modeling approach. The methodology is demonstrated using (simplified) real-world engineering case studies based on the Arrowhead Framework and platform.

Through the increasing complexity and dynamics of industrial automation scenarios, the notion of Systems of Systems (SoS) has gained importance in this field. Here, interconnected constituent (hardware as well as software) systems collaborate in order to achieve common goals and to increase the efficiency of certain industrial applications.The Arrowhead Tools project aims at proposing a comprehensive, flexible platform for supporting SoS engineering in its every phase, in the form of an engineering toolchain. Thereby, although the SoS operation aspect has been already elaborated on, the design phase and the usage of design artifacts as part of a continous tool interoperability scenario received less attention so far. In this paper, we describe such a toolchain interoperability scenario, paving the way towards an established, integrated solution, by linking systems modeling practices with SoS operational management. In particular, we propose a customtailored abstract SysML profile for Arrowhead SoS design, and a prototype implementation for a bidirectional link between SoS models and a tool for managing Arrowhead SoS via a customtailored textual format. We illustrate the approach through a realistic industrial application.

Refactorings constitute an effective means to improve quality and maintainability of evolving object-oriented programs. Search-based techniques have shown promising results in finding optimal sequences of behavior-preserving program transformations that (1) maximize code-quality metrics and (2) minimize the number of changes. However, the impact of refactorings on extra-functional properties like security has received little attention so far. To this end, we propose as a further objective to minimize the attack surface of programs (i.e., to maximize strictness of declared accessibility of class members). Minimizing the attack surface naturally competes with applicability of established MoveMethod refactorings for improving coupling/cohesion metrics. Our tool implementation is based on an EMF meta-model for Java-like programs and utilizes MOMoT, a search-based model-transformation framework. Our experimental results gained from a collection of real-world Java programs show the impact of attack surface minimization on design-improving refactorings by using different accessibility-control strategies. We further compare the results to those of existing refactoring tools.

Design flaws in object-oriented programs may seriously corrupt code quality thus increasing the risk for introducing subtle errors during software maintenance and evolution. Most recent approaches identify design flaws in an ad-hoc manner, either focusing on software metrics, locally restricted code smells, or on coarse-grained architectural anti-patterns. In this paper, we utilize an abstract program model capturing high-level object-oriented code entities, further augmented with qualitative and quantitative design-related information such as coupling/cohesion. Based on this model, we propose a comprehensive methodology for specifying object-oriented design flaws by means of compound rules integrating code metrics, code smells and anti-patterns in a modular way. This approach allows for efficient, automated design-flaw detection through incremental multi-pattern matching, by facilitating systematic information reuse among multiple detection rules as well as between subsequent detection runs on continuously evolving programs. Our tool implementation comprises well-known anti-patterns for Java programs. The results of our experimental evaluation show high detection precision, scalability to real-size programs, as well as a remarkable gain in efficiency due to information reuse.

Numerous topology control algorithms for wireless sensor networks exist. Typically, these algorithms optimize general network metrics like the transmission range of sensors. Being of general nature, they suit application-specific requirements insufficiently; e.g., application-specific communication patterns may favor links that the general algorithm will remove.